[FFmpeg-devel] pipeline multithreading

[Daniel Oberhoff]

Hi,

From what I gather the filter graph is utilizing modern multicores by “striping” where filters support it, i.e. an image is divided in stripes and the filter gets called in separate threads for separate stripes. I was wondering if there is or will be pipeline multuthreading, i.e. with a setup such as

inout -> filter1 -> filter2 -> output

some threads processing frame n in the output (i.e. encoding), other threads procesing frame n+1 in filter2, others processing frame n+2 in filter1, and yet others processing frame n+3 decoding. This way non-parallel filters can be sped up, and diminishing returns for too much striping can be avoided. With modern cpus scaling easily up to 24 hardware threads I see this as neccessary to fully utilize the hardware.

Is this already done? Or are there plans? If it is not done, how much more work is it? Could I help (not promising much, but I may find time, especially as this limits us…).

Best

Daniel

P.S: please CC answers back to me, as I pipe ffmpeg mails into a folder I only check occasionally..